Mitochondrial Calling

Typically, there are approximately 100 mitochondria in each mammalian cell, and each mitochondrion harbors 2–10 copies of mitochondrial DNA (mtDNA). For example, if 20% of the chrM copies have a variant, then the allele frequency (AF) is 20%. This is also referred to as continuous allele frequency. The expectation is that the AF of variants on chrM is anywhere between 0% and 100%.

DRAGEN processes chrM through a continuous AF pipeline. In this case, a single ALT allele is considered, and the AF is estimated, and can be anywhere between 0% and 100%.